Appearances often deceive. Steven Pinker’s “The Better Angels of Our Nature” landed on my desk in the immediate aftermath of that terrible massacre in Norway. As I read the book, Syrian forces slaughtered pro-democracy protesters, riots engulfed English cities, and murders punctuated the news. But, if we believe Pinker, all this violence is just the background noise behind a relentless paean of peace.

He’s probably right. The world today is less violent than it has ever been. We’re living through the longest period without war between great powers since Roman times. All other categories of violence — murder, rape, child abuse, wife-battering — have also declined. Pinker thinks his revelations are Earth-shattering, but, in fact, he’s merely proved something that most historians have long accepted, namely that there’s no reason to be nostalgic about the past.

Most people, however, think they live in uniquely violent times, a popular misconception that encourages panic. Travelers frightened of terrorism spurn airplanes in favor of much more dangerous cars. Parents worried about sidewalk pedophiles drive children to school and thereby exponentially increase the risks they face. The world seems violent partly because films, Web sites, video games and music pummel us with images of brutality. Parents cringe when Ice Cube boasts: “I can act like an animal, ain’t nothin’ to it/Gangsta rap made me do it.” Pinker, however, thinks that’s simply hot air — pretend violence has replaced the real thing.

The rather unfortunate title of this book will encourage readers to assume that this is another installment in self-help spiritualism encouraging us to befriend our angels. In fact, the book is populated not by winged cherubs, but by cold rationalists. The bibliography stretches to 32 pages, testimony to Pinker’s zealous research. More than 100 graphs assess the extent of violence and chart the evolution of control mechanisms. Many of those graphs look remarkably similar: A diagonal line moves from top left to bottom right, charting how violence has declined.

Statistics, however, also deceive. Pinker’s avalanche of evidence camouflages dodgy analysis. For instance, he frequently mentions that blacks in America are peculiarly susceptible to violence. Statistics bear that out, but the painful truths that lie beneath those raw numbers need careful handling. Instead, Pinker cites the connection between matrimony and passivity, arguing that blacks are violent in part because they are notoriously unenthusiastic about marriage: “Perverse welfare incentives . . . encouraged young [black] women to ‘marry the state’ instead of the fathers of their children.” Reckless analysis of this sort can foster dangerous bigotry.

‘The Better Angels of Our Nature’ by Steven Pinker (VIKING)

Pinker aggressively discounts economic explanations, arguing that violence rose from the late 1960s to the ’90s (when times were good) and fell after 2001 (when recession hit). Yet that glib assessment ignores how specific social classes have fared. Some groups that never benefited from postwar prosperity grew impatient with inequality by the late 1960s. Pinker fails to see how violence became a logical expression of anger for them. “The urban riots . . . [of] the 1960s,” he argues, “were not a part of the civil rights movement and erupted after most of its milestones were in place.” That’s nonsense. The riots were a response to the limitations of the civil rights movement, namely its inability to address material inequality as opposed to legal discrimination. They led directly to the Kerner Commission report of 1968, which inspired positive programs to address inner-city problems. A generation later, those programs contributed to the decline in violence that Pinker celebrates.

Pinker’s analysis of the ’60s is equally simplistic. The violence of the period 1970-95, he argues, resulted from “a plummeting of trust in every social institution.” This “decivilization” — the fault of ’60s radicals — spread like a contagion. Yet Pinker ignores the fact that organs of the state perpetrated the really terrible violence of the ’60s, for instance, in Vietnam, Chicago and Montgomery. In other words, authority was worthy of distrust. In any case, most ’60s radicals settled into respectable middle-class conformity after their brief flirtation with radicalism. Are we to believe that while they spurned violence, an entirely separate and unrelated group of urban desperadoes were so infected by their ideology that they let loose three decades of mayhem? Where’s the evidence?

The status quo back then deserved to be toppled. As Pinker shows, ’50s complacency sheltered lynchings, wife beatings, child abuse and terrible cruelty. The so-called rights revolutions, rooted in the ’60s, significantly improved the lives of women, minorities, gays and children and reduced violence against those groups. So how is it that the revolt against authority was both so very good and so very bad? Pinker ignores that contradiction.

Though a gifted psychologist, Pinker is a pretty mediocre historian. Myth and anecdote are used extensively when they suit his purpose. His source on the Altamont riot is Wikipedia. But the really big problem with this book is that the complexity of the past doesn’t lend itself to bar graphs, bullet points and sweeping generalizations. Pinker’s most ludicrous assertion comes when he addresses the connection between violence and low intelligence. He measures the IQ of presidents (don’t ask how) and concludes that “for every presidential IQ point, 13,440 fewer people die in battle, though it is more accurate to say that the three smartest postwar presidents, Kennedy, Carter, and Clinton, kept the country out of destructive wars.” (At that point, violence overcame me — I threw this book across the room.) Kennedy (most serious historians agree) took America into the quagmire of Vietnam, a very destructive war. And what of Eisenhower, the least bellicose of postwar presidents? Was he intelligent or just lucky?

“Better Angels” is fascinating but also deeply flawed. Pinker deserves congratulation for trying to explain why violence has declined. His basic point is valuable, namely that the four angels of empathy, self-control, morality and reason have gradually triumphed over the more passionate and sanguinary aspects of our nature — our inner demons. Progress owes much to technology, particularly in communication. Television, telephones, e-mail and air travel have encouraged a sharing of cultures. Because we know and understand our world better, we are less likely to poison it with violence. That is a worthy argument, and one upon which strategies for controlling violence can be built. But there’s too much in this book that is simply nonsense. Confidence is Pinker’s biggest impediment; it leads him to impressionistic judgments unsupported by facts. He needs a more assertive editor to tell him when he’s spouting rubbish. A shorter book, purged of self-indulgent pontification, would have been a better book.

Pinker believes that the decline of violence is testimony to the triumph of classical liberalism — the ideas of Hume, Locke and Voltaire. The Age of Enlightenment caused a ripple of reason to spread across the world, gradually vanquishing unbridled emotion. The head imposed itself on the heart. But therein lies a problem. As he points out, the most powerful country on Earth is composed of two cultures. The blue states resemble liberal Europe, which has led the way in taming violence. The red states, however, have more in common with those nations less successful in stifling aggression. In other words, a peaceable future depends in part on the culture war currently raging in America. The outcome of that contest might determine whether those graphs of violence maintain a downward diagonal.

Gerard DeGroot is a professor of history at the University of St. Andrews in Scotland.